Sheet separating method and apparatus



April 10, 1934. E, HUNTER 1,954,480

SHEET SEPARATING METHOD AND APPARATUS Filed May 51, 1932 ,2 Sheets-Sheetl INVENTOR Patented Apr. 10, 1934 SHEET SEPARATKNG METHOD AND APPARATUSPercy E. Hunter, Pittsburgh, Pa.

Application May 31, 1932, Serial No. 614,604

15 Claims.

My invention relates to a method of and apparatus for separating sheets,and more particularly to the separation of metal sheets such as arehot-rolled in packs. The invention is also ap- 'iplicable to theseparation of metal sheets after they have been box annealed, or whichare bound tightly together through the annealing process and their ownweight.

In the hot rolling of lighter gauges of sheet 9" metal the sheet barsare passed repeatedly through rolls until they are of suflicientlyreduced thickness, and are doubled and reheated repeatedly until theoriginal bars may consist of eight or more sheets in a single pack. Therolling pres- '1 sure causes the sheets or layers of the pack to adheretightly together and these packs must be opened or separated after theyhave been sheared. In the process of shearing packs, the edges of thethin sheets are dragged down or burred over one another, and in somecases where the shear knives are dull, the drag on the upper sheet maycarry it down over the edge of the entire pack, thereby causing thesheets to be more tightly bound together.

The sheets of the pack are commonly separated or opened by bending onecorner of the pack to effect slight separation of the sheets at suchcorner, and then manually stripping the sheets oii, one by one. Evenunder favorable conditions this is a tedious and laborious operation,and when the sheets stick together tighter than usual, tools such aswedges are required to separate the sheets. In many cases, the sheetsbecome damaged and have to be scrapped.

This invention relates to a method for opening packs by bending a packclose to the sheared edge at one or more corners or along one or moresides, very abruptly, by means of rolls or dies, so as to overcome thestrength of the adhesion between sheets and to break the mechanical bondformed in shearing the pack. This is accomplished by bending the cornersor sides of the pack as close to the sheared edge as possible around assmall a radius as practical, in order to stretch the sheets a minimumamount and draw the edge of each sheet away from the edge of the sheetadjacent thereto. If a pack be bent around a large radius for the samenumber of degrees, the difference between the length of arc on theinside and on the outside of the pack would be the same as for the samethickness of material bent around a smaller radius, but the length ofarc would be much greater, and the material would therefore stretch moreand not exert as great a pull between adjacent sheets forming the pack.

The adhesion between the individual sheets is so great that if a pack bebent over a large radius the individual sheets will be stretched, but ifbent over a very small radius close to the edge of the pack, thestrength of the material is greater than s the adhesion and will causeone plate to slip over the other, overcoming the adhesion and destroythe mechanical bond, and a reversal of the bend will cause the edges ofthe individual sheets to fan out surhciently to either to permit gettinghold of the individual sheets to pull them apart, or to introduce aseparating force between the individual sheets.

Some of the ways in which my invention may be practised are shown in theaccompanying drawings, wherein Figure l is a longitudinal sectional viewof a machine; Fig. 2 is a cross sectional view of the press or bendingmechanism; Fig. 3 is a View taken on the line III-III of Fig. 2, showingpack ejector actuating mechanism; Figs. 4, 5 and 6 are fragmentary viewsof the press of Fig. 2, showing the bending elements of one side thereofin various positions of bending movement; Fig. 7 is a sectional planview of a portion of the structure of Fig. 1; Fig. 8 is a view taken onthe line VIII-VIII of Fig. 7; Fig. 9 is a vertical sectional viewshowing another form. of sheet separating aparatus; Fig. 10 is afragmentary plan view thereof, and Fig. 11 shows another manner in whichadhering sheets may be separated.

Two opposite edges of a pack are bent on a bending machine or presser12, as above-explained, the pack then being passed through fiatteningrollers indicated at 13, and t0 the separating or opening apparatusindicated at 14 (Fig. 1).

The presser comprises side frame members 15 held in assembled relationby bolts or tie rods 16 and a base plate 17. The base plate 17 ismounted between and secured to the side frame members 15 and is shown assupporting plunger housings 18 in position adjacent to the side frames,each housing carrying plungers 19 that are yieldably held in theiruppermost positions by springs 20 that surround bolts 21 which limitupward movement of the plungers. Each housing 18 has a pair ofupwardly-extending ribs or projections 22 about which the edges of apack 23 are bent as shown in Figs. 4, 5 and 6, and as hereinafterdescribed.

A cross head or presser head 25 is disposed between the frame members15, and has extensions 26 at its ends that are slidably supported in vertical guideways formed in the sides of frame members 15. The presserhead 25 is reciprocated vertically by means of a crank shaft 27 that isjournailed in the uper edges of the frame members 15, and is driven fromany suitable source of power. Connection between the cranks of theshafts 2'7 and the presser 25 is had through a pair of links orconnecting rods 28.

The presser 25 supports plunger housings 29 in alignment with theplunger housings 18, the housings 29 carrying plungers 30 that areyieldably held in their lowermost positions by springs 31, bolts 32being provided to limit downward movement of the plungers. Four plungers30 and four plungers 19 are shown in the drawings, and these can bevaried in number to suit various conditions, such as the sizes of packsupon which it is desired to operate. A slot 33 is provided near eachside of the presser 25, and the outer walls of such slot are inclined asat 34 to provide a pack-centering and bending surface for the pack. Thatportion of the slot wall immediately above the bevelled portion 34 maybe roughened or serrated as shown at 35 in Fig. 4, in order to exert astriping or abrading action on the edges of the sheet to loosen thesame.

When a pack of sheets has been placed in the bending machine, the shaft2'7 is set in motion to lower the cross head. As the cross headdescends, the opposite longitudinal edges of the pack are engaged by theinclined walls 34 to center the pack, and then bend it down, as shown inFig. 4, the pack being gripped between the pairs of cooperating plungers30 and 19, to prevent movement of the pack during bending of its edges.

Continued downward movement of the presser head 25 carries the plungerhousings 29 into engagement with the pack, as shown in Fig. 5, and bendsthe edges of the pack around the ribs 22, through movement of the packbodily in a direction perpendicular to its plane. In Fig. 5 this secondbending operation is shown in its initial stage, at which time the edgeof the sheets of the pack are caused to be moved across the serrations35 and across the ribs 22. The springs 31 may yield sufliciently topermit the plungers 30 to go solid, and the pack 23 is bent to theposition shown in Fig. 6.

During the final stage of this second bending operation the springs 20are compressed, while the pre-bent edge portions of the pack are pulledacross the ribs 22 and then bent in the opposite direction, therebyreversing the drawing or slipping action of the edge portions of thesheets relative to each other. The extent of movement of the pack duringthe second bending operation is such that the entire edge portion atopposite sides of the pack is re-bent to a position at right angles tothe plane of the pack. This operation is expeditiously effected bymerely moving the pack relative to the ribs 22 a distance substantiallyequal to or greater than such width of the edge portion of the pack asis desired to subject to the bending operation.

During the raising movement of the presser head 25 the springs 20 andtheir plungers 19 will raise the pack from between the bending ribs 22.

' When the presser head 25 is raised sufficiently, the

pack is released from the gripping force of the plungers l9 and 30 and acam 35' carried by the shaft 27 engages a lever arm 36 pivotally securedat one end to one of the side frames 15 (Figs. 1, 2 and 3). The otherend of the arm 36 is secured to a rod 37 which is connected to a leverarm 38, the arm 38 being carried by a shaft 39 that is suitablyjournalled at its ends to the side frames 15. The shaft 39 carries anarm 40 which has connection with one end of a rod or link 41, the otherend of the link 41 being connected to a rod 42 which extends between apair of rocker arms 43. The arms 43 are pivotally secured at their lowerends to the base plate 17, their upper ends being disposed to the rearof the pack of sheets in the presser machine.

As the arm 36 is swung upwardly by the action of the cam 35, the rockerarms 43 are moved into engagement with the rear edge of the pack by theconnections above-described and the pack is moved forwardly to theflattening rolls 13. At the end of the lifting movement of the cam 35,the cam passes out of engagement with the arm 36 and a spring 44 securedto the lower end of the rod 37 causes the rocker arms 43, and theoperating connections to assume their normal positions. Thepack-ejecting mechanism is preferably actuated and restored to itsnormal position before the completion of the lifting movement of thecross head 25, so that another pack of sheets may conveniently beinserted in the presser machine.

As shown more clearly in Fig. 7, the first of these rolls 46 has itsends tapered, so that the ends will force the sharply upturned edges ofthe pack 23 outwardly and downwardly, the said edges of the pack beinginitially bent downwardly through the impact thereof with the rollsunder the action of the above-described advancing mechanism. The nextroll 47 is of smaller taper at its ends to force such bent edges furthertoward flattened position, while roll 48 completes the flattening of thesheet.

As explained heretofore, this operation results in loosening of thesheets at the edges of the pack, and I effect complete separation oropening of the sheets by means of air or other fluid pressure, ashereinafter described.

As the packs leave the flattening rolls, they enter between two conveyerbelts 52 and 53 that are driven in any suitable manner, the adjacentsides of these belts traveling in the same direction. The upper belt 53serves primarily to prevent too great vertical movement of separatedsheets, and to advance any sheet which is blown into contact therewith.The belts, of course, pass around suitable pulleys which are driven inany convenient manner.

An elongated orifice 54 is positioned at each side of the conveyerbelts, and is supplied with fluid pressure from a supply line 55 andbranch pipes 56. As the sheets are advanced by the belt 52, with theirlongitudinal edges extending into the slots 54, air or other fluid underpressure is blown against the edges of the sheets and enters between thesheets of the pack. The edges of the sheets need not be previouslyseparated or loosened throughout their length, since even if only smallopenings are present for the entry of fluid pressure, the force of suchpressure will be multiplied many times over the surfaces of the sheets,and the expansive separating force is very great even with relativelylow air pressures. The lower run of the belt 53 is spaced such distanceabove the upper run of the belt 52 that it will not interfere with thenecessary separating movement of the sheets.

In order that packs of sheets of various widths may be operated upon,the presser machine, the flattening rolls and the separating apparatusare made adjustable. In the presser machine, one of the plunger housings29 is slidably supported or hung on the cross head 25 by means offlanged ribs 60, the ribs extending throughout slots in the cross head.

A stud bolt 61 is threaded into the housing 29,- and extends through theside of the cross head and through the side frame 15. A hand wheel 62 isrotatably mounted on a bracket 63 which is secured to the side of thecross head 25, the frame 15 being cut away sufiiciently to permitvertical movements of the bracket due to vertical reciprocation of thecross head. The bolt 61 has threaded connection with the bushing of thehand wheel, so that when the wheel is rotated in one direction or theother, the plunger housing will be moved toward or away from the plungerhousing 29 at the opposite side of the machine. Likewise, the plungerhousing 18 beneath the adjustable housing 29 is adapted to be movedtoward and away from its opposite housing 18, by means of abolt 64 andhand wheel 65. If desired, each of the plunger housings 29-29 and l818may be made adjustable.

As to the rolls 46, 47 and 48, they are provided with clamps or setscrews 49 by means of which the set of rolls at one side of the machine,or both sets, may be secured to their shafts at the, desired positionfor packs of varying widths.

With respect to the separating apparatus, the elongated nozzle 54 isshown as slidably supported on a bracket 57 and adjustable toward andfrom the edges of the pack by means of a screw 58 that has threadedengagement with the nozzle (Figs. '7 and 8). This adjustment permits thenozzle to be brought to proper position with respect to packs of varyingwidths. The nozzle at the other side of the pack may or may not beadjustably mounted.

Referring now to Figs. 9 and 10, I show a holding frame '70 for a pack.The upper and lower edges of the pack may be flexed or bent and thenstraightened, previous to placing them in the holder, if desired. At itslower edge, the holder carries an elongated flared mouth nozzle 71, andat its upper edge a nozzle '72. These nozzles correspond to the nozzles54 and are supplied with fluid under pressure, from a suitable source.If desired, one of the nozzles can be dispensed with, and fluid pressuresupplied only at one edge of the pack, since the fluid pressure can bedirected entirely through the pack from one side thereof, but I preferto supply the fluid pressure from two opposite edges of the pack.

The frame '70 is provided with verticallyspaced guide bars '73 that areflared at their ends to facilitate sliding of a pack into the nozzlesand at their intermediate portions, serve as retaining bars to partiallyconfine the sheets so that they will not be blown too far apart, thebars, however, having spaced relation to the sides of the pack so that aproper sheet separation may be effected.

In Fig. 11, I show a hand tool which may be employed, particularly whentwo sheets have not been entirely separated when operating upon the packas a whole. This tool consists of a widemouthed nozzle 74 supplied withfluid pressure, and is inserted between the sheets and may be moved tobring it in proximity to adhering portions of the sheets, thereby moreeffectively concentrating the fluid pressure than if the nozzle wereleft in a fixed position at one edge.

The bends at the edges of the sheet, as shown in Figs. 4 and 6, are madeas closely as possible to the edge thereof. For example, the first bendmay be made at approximately /4 inch from the edge of the pack, and witha inch radius, to more effectively overcome the adhesion of the sheets,and break the mechanical bond thereof,

as set forth, at length heretofore. The separating force is very greatwhen bending the pack to a 90 are within so small a radius, and muchgreater than in the case of a 90 are bent on a one inch radius, forexample.

While I have herein more specifically described the bending of sheetsalong one or more edges, it will be understood that the inventioncontemplates also the bending of packs along diagonal lines, fromedge-to-edge, adjacent to the corners of the packs, and introducingfluid pressure between the sheets at those portions of the edges whichare adjacent to the corners.

The structure of Figs. 1 to 6 may, of course, be employed in the bendingof the packs along the diagonal lines at the corners, the packs beingplaced in the machine in a diagonal position instead of with their edgesparallel to the sides of the machine. The bending of the packs acrossthe corners instead of along their longitudinal edges has the furtheradvantage that a single machine, without adjustment of the bending elements, may be employed to bend packs of various sizes, by turning thepacks toproper diagonal position, so that their corners are under thebending elements 19. Thus a wide pack would have its edges placedparallel to the horizontal axis of the machine, and a small pack mightbe so placed that a line connecting diagonal corners would be perhaps atright angles to the path of movement through the machine.

I claim as my invention:-

l. Apparatus for separating sheets of a pack which comprises anelongated nozzle for receiving the longitudinal edge of a pack, meansfor supplying fluid under pressure to said nozzle, a conveyer forcarrying the pack along said nozzle, and a traveling conveyer memberspaced abovethe first-named conveyer for limiting upward movement of thesheets and for advancing sheets engaged thereby.

2. The combination with sheet-pack bending means, of an ejector operatedby the bending mechanism to discharge bent packs, flattening rolls forreceiving and advancing said packs, a conveyer positioned to receive thepacks advanced by the said rolls, and a fluid pressure nozzle positionedto discharge against the edges of packs while traveling with saidconveyer.

3. The method which comprises bending one edge of a pack of sheets outof the plane of the pack, gripping the pack, and moving the same bodilyin a direction perpendicular to its plane while maintaining the bentedge portion thereof,

along its axis of bending movement, against l movement in suchdirection, to cause movement of the bent portion across said axial line.

4. The method which comprises bending one edge of a pack of sheets in agiven direction out of the plane of the pack, and moving the pack bodilyin said direction while maintaining the bent edge portion thereof alongits axis of bending movement, against movement in such direction, tocause movement of the bent portion across said axial line.

5. The method which comprises bending one edge of a pack of sheets in agiven direction out of the plane of the pack, and simultaneously movingthe pack bodily in said direction, while maintaining the bent edgeportion thereof along its axis of bending movement, against movement insuch direction, to cause movement of the bent portion across said axialline.

6. The method which comprises bending one edge of a pack of sheets outof the plane of the IGO- pack, gripping the pack, moving the same bodilyin a direction perpendicular to its plane while maintaining the bentedge portion thereof along its axis of bending movement, againstmovement in such direction to cause movement of the bent portion acrosssaid axial line, restoring the bent portion to the plane of the pack,and introducing fluid under pressure, between the sheets, at said edge.

7. The method which comprises supporting one portion of a pack of sheetsfor bending movement on an axis parallel to the plane of the pack,gripping the other portion of the pack at points adjacent to said axialline, and bodily moving said gripped portion of the pack in a directionperpendicular to the plane thereof, to bend the pack along said axialline, and continuing the said movement to cause said one portion of thepack to enter the bending zone progressively.

8. The method which comprises bending one edge portion of a pack ofsheets out of the plane of the pack, supporting said portion along itsaxis of bending movement against movement in a direction perpendicularto the plane of the pack,

gripping 1e pack at points adjacent to said axial line and moving thesame in a direction perpendicular to the plane of the pack, to bend andmove said portion in the direction opposite to the initial bendingmovement thereof, and applying fluid pressure, between the sheets, atsaid edge portion.

9. Sheet-separating apparatus comprising means for gripping a pack ofsheets at points removed from an edge thereof, means for supporting thepack along a line adjacent to said edge, means for bending said edge ofthe pack at one side of said supporting means, and means engaging thepack adjacent to said supporting means and movable in directionsperpendicular to the plane of the pack, for moving the pack bodilyrelative to said supporting means, thereby bending the pack at the otherside of said supporting means.

10. Sheet-separating apparatus comprising means for gripping a pack ofsheets at points removed from an edge thereof, a supporting memberengaging the pack at one side along a line adjacent to said edgethereof, a pair of laterallyspaced bending members at the other side ofthe pack in position to receive said supporting member therebetween, andmeans for moving said bending members relative to said supporting memberin directions perpendicular to the plane of the pack, and relativelypast the plane of the pack, the pack being bodily depressed relative tosaid supporting member during the bending operation.

11. Sheet-separating apparatus comprising a pair of opposed pressermembers, for receiving one edge of a pack of sheets therebetween, one ofsaid members being movable relative to the other member in directionsperpendicular to the plane of the pack, a longitudinally-extending ribon the face of one of said members, means on the other member forbending said edge over said rib in opposite directions, and yieldablysupported gripping devices carried by said members for engaging the packalong a line removed from the bending zone.

12. Sheet-separating apparatus comprising means for supporting a pack ofsheets along a line spaced inwardly of an edge portion thereof, meansfor bending said edge portion downwardly at the outer side of saidsupporting means, and means movable in directions perpendicular to theplane of the pack, for depressing the pack bodily at the inner side ofsaid supporting means, thereby rebending the bent edge portion in theopposite direction so that it lies in a plane substantially at rightangles to the plane of the pack.

13. Sheet-separating apparatus comprising a pair of spaced parallelrails, for supporting a pack of sheets adjacent to opposite edgesthereof, a cross-head above said rails, a pair of downwardlydependingbending members carried by said crosshead opposite each rail, each pairof bending members being laterally spaced to engage the upper side ofthe pack of sheets along lines adjacent to the outer and inner sides ofthe associated rail, and means for lowering said crosshead and mov ingsaid bending members below the plane of the pack, for bending said edgesof the pack over the said rails in opposite directions, the pack beingdepressed between said rails during the bending operation.

14:. Sheet-separating apparatus comprising a pair of spaced parallelrails, for supporting a pack of sheets adjacent to the opposite edgesthereof, a crosshead above said rails, a pair of downwardly-dependingbending members carried by said cross-head opposite each rail, each pairof bending members being laterally spaced to engage the upper side ofthe pack of sheets along lines adjacent to the outer and inner sides ofthe asso ciated rail, and means for lowering said crosshead and movingsaid bending members below the plane of the pack, for bending said edgesof the pack over the said rails in opposite directions, the pack beingdepressed between said rails during the bending operation, the lowerends of the outer bending members being inclined to engage one of saidedges of the pack, for initially centering the pack relative to saidrails.

15. The method which comprises bending a pack of sheets in one directionalong a line adjacent to an edge thereof, gripping the pack adjacent tothe bending zone, during the bending operation, and shifting the grippedportion of the pack in a direction to cause the bent edge portionthereof to be rebent progressively in the opposite direction by slidingmovement thereof across the axial line of bending movement.

PER-CY E. HUNTER.

